It is often desirable to provide a venting mechanism for closed containers to allow equalization of pressure. For example, when storing a container with warm food in a refrigerator the container may be damaged or lose its seal due to warping of the lid when the warm air cools and contracts.
Another common example where a venting mechanism is desirable is with baby bottles where, without a venting mechanism, a partial vacuum typically results upon drinking which can lead to difficulty in suckling and a need to release this vacuum by taking the bottle out of the baby's mouth to allow air to flow in via the nipple's suckling aperture. To overcome this issue, many modern baby bottle designs include a venting mechanism. Most such venting mechanisms comprise a vent with a one-way valve in the nipple, usually in the nipple's flange; however some venting mechanisms are located at the bottom of the bottle, requiring a re-design of the bottle with a specific shape and additional parts.
However, such venting mechanisms are commonly fraught with functional/practical issues, for example they can allow leakage of baby formula and the vent can be undesirably affected if the nipple ring/collar is screwed shut too tightly or the collar sticks to the nipple flange. Venting devices in these nipple-integral vents are often skirts depending from the nipple's sealing flange that are designed to form a one-way valve in association with the inner wall of the bottle's neck. Such skirts tend to readily allow leakage, presumably due to slight or not so slight deformation, upon even small movement of the skirt/nipple; and which occurs whenever the nipple is secured to the bottle by the collar. This movement is most likely due to twisting of the nipple flange upon screwing of the collar (causing a rotational movement; or, a deformation due to sticking between the nipple flange and the bottle and/or collar). However such movement may alternatively (or additionally) be due to front-back or side to side movement.
In other words, the performance of most mechanisms for ventilating containers/bottles, especially baby bottles, the vent/valve is affected by the user, in particular upon closing the container/bottle. Bottles with a venting mechanism having a one-way vent valve integral with the nipple, or on the bottle neck as in the prior art, tend to leak due to a deformation of the valve caused by screwing the collar to secure the nipple on the bottle. The deformation is typically in the form of waviness or wrinkling of a so-called skirt valve. In addition, one-way skirt valves, e.g. as described in U.S. Pat. No. 2,736,446 and U.S. Pat. No. 4,613,050 require very tight tolerances (precise manufacturing) so that the skirt valve seats properly on the bottle neck.
To avoid some of the above issues, venting mechanisms located at the neck/mouth/rim of the bottle, but not integral to the nipple, have been disclosed for example in CN 2011/75461 (Zhujin Wang); and US 2009/0255895 (Kiehne); U.S. Pat. No. 2,876,773 (Witz); U.S. Pat. No. 5,284,261 (Zambuto); U.S. Pat. No. 5,791,503 Lyons and US 2006/262041 (Smith). However, these venting mechanisms suffer from one or more drawbacks including at least that they take up a significant space of the mouth opening; and/or the components themselves cannot be made as a one-piece unit; and/or the user must make an adjustment to control the venting aspect; and/or they are not easy to clean; and/or the mechanisms are none-the-less not designed to prevent movement; and or they are relatively complicated in design or in manufacturing.
As two of the biggest issues with baby bottle venting mechanisms are leakage and cleaning, is an object of the present invention to provide an improved container and venting mechanism assembly that addresses at least these issues. Another object is to provide such an assembly that will not be affected by the user, in particular by the closing of the bottle (screwing the collar).